Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
1246 AM EDT Mon Jun 08 2020
Valid 12Z Thu Jun 11 2020 - 12Z Mon Jun 15 2020
...Overview and Guidance/Predictability Assessment...
Upper pattern will transition to a trough/ridge/trough orientation
from west to east by the end of the week as ex-Cristobal leaves
the picture. Models and ensembles remain in good agreement overall
with the most spread out of the Pacific. Relied on a nearly even
blend of the 12Z ECMWF and 12Z/18Z GFS with their ensemble means
due to timing and amplitude differences in the Northeast between
the deterministic runs. This maintained good continuity over much
of the CONUS, with the exception of an added weak system out of
the northeast Pacific this weekend.
Ocean system near Bermuda may attempt to retrograde
westward/northwestward toward the East Coast as either an occluded
or subtropical entity, or perhaps just a weak surface trough. NHC
will continue to monitor this system in their outlooks.
...Weather/Hazard Highlights...
Warm temperatures (about 5-15 deg F above normal) will spread from
the Rockies to the Plains later in the week into the weekend just
ahead of a slowly moving cold front. That system will bring cooler
than normal temperatures to the Pacific Northwest (about 5-15 deg
F below normal) especially on Saturday. Farther to the east,
temperatures will trend cooler through the period but within about
10 degrees of normal.
Rainfall will generally by light nationwide after the heavy rains
from Cristobal in the short term. Some modest rain may accompany
the front over the East and into the Southeast with perhaps a
surge on Sunday along the East Coast as the front slumps eastward.
Over the Northwest, some rainfall is likely especially in the
terrain as the lead front moves through the northern Rockies/Great
Basin Thu/Fri. There may be a bit more widespread rainfall by next
week over the Plains once the system clears the Rockies.
Fracasso
Additional 3-7 Day Hazards information can be found on the WPC
medium range hazards chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range 500mb heights, surface systems, weather grids,
quantitative precipitation, winter weather outlook probabilities
and heat indices are at:
https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif
https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html
https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml
https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4
https://www.wpc.ncep.noaa.gov/heat_index.shtml